A Polish state archive has released documents which allegedly show that democracy leader and former president Lech Walesa collaborated with the communist secret police in the 1970s, before he took leadership of a movement that eventually helped topple communism.

The Institute of National Remembrance made parts of the files available to journalists Monday. Their authenticity has not been verified.

Walesa denies collaborating with the secret police, and his supporters see the rush to release the documents as an attempt to smear his legacy.

The release of the papers, which surfaced last week, comes after the rise to power last year of the right-wing Law and Justice party, led by longtime Walesa foe Jaroslaw Kaczynski.

Law and Justice leaders insist the historical truth of Walesa's past should be clarified.